The present invention relates generally to highway safety systems and, more particularly, to spacer blocks for attachment of guardrails to support posts.
Guardrails are typically installed along highways as components in roadway safety barrier systems. The guardrails commonly used are usually formed as strips of material, typically twelve (12) gauge galvanized steel. Other materials commonly used in guardrail fabrication include aluminum, steel, fiberglass, or even synthetic materials. Most segments of guardrail are approximately twelve (12) feet in length and about ninety (90) pounds in weight.
At least one configuration of a guardrail used includes a corrugation forming an undulating cross section. The undulating cross section is employed in its capacity to absorb energy from the impact of an out of control vehicle. Such energy absorption is desired in an effort to prevent the vehicle from leaving the roadway or at least to influence the direction of the vehicle prior to it leaving the roadway. Typically, corrugated beams are about nine (9) inches wide, have two crowns and are shaped substantially like the letter xe2x80x9cWxe2x80x9d. An alternate corrugated guardrail embodiment is known in the industry as a thrie-beam guardrail. Thrie-beam guardrails typically have three crowns and are generally about one-third (⅓) wider than a conventional, two-crown, or xe2x80x9cWxe2x80x9d, guardrail.
In most roadway safety barrier systems, a plurality of guardrails are typically linked together at their distal ends, either end to end, or overlapping, and are supported by a plurality of vertically oriented support posts. Among the support post configurations typically used are xe2x80x9cI-beam,xe2x80x9d round or square posts. The support posts used may be fabricated from a variety of materials including wood, metals such as aluminum, steel, etc. Some support posts may also be formed from polymer or fiberglass materials. In place, driven into the ground a distance from the edge of the roadway and from one another, the support posts will typically yield under a certain amount of pressure either by moving within the ground or by bending in accordance with the deformation of the guardrail. Preferably, the support posts do not break off at ground level. Yielding or bending is preferred in an effort to assist the guardrail in dissipating the impact force received from an out of control vehicle.
In a typical roadway safety barrier system, a spacer block is disposed between the guardrail and the support post such that the guardrail may be maintained a distance from the support post. The spacing provided by the spacer block preferably helps keep an automobile""s wheels from coming into contact with the support posts and initiating a roll of the vehicle. In addition, the guardrail provides a rail or track for guiding the vehicle and providing at least some response time for the driver to regain control of the vehicle.
Conventional spacer blocks are typically made of wood. However, wood as a material for spacer blocks has many shortcomings. Among wood""s shortcomings as a spacer block material are that it deteriorates over time, it is excessively heavy, it can give installers splinters and it typically contracts and expands with seasonal changes. In addition, wood tends to leach out the chemicals typically used for pressure treatment, which chemicals may be toxic to the environment. While there are some plastic spacer block substitutes on the market, they are generally deficient in that they are typically wood block designs formed from plastic.
In most installation instances, it requires two to three people to attach a twelve (12) foot section of guardrailing to support posts when using conventional spacer blocks. In the effort, installation typically requires one person to hold the guardrail while another person aligns and holds the spacer block in position. A third person is often required to insert bolts or other attachment means through each system piece for securitization thereof.
In accordance with teachings of the present disclosure, a guardrail support, attachment and positioning block is provided. In one embodiment, the block preferably includes a pair of side-walls coupled to a top and a bottom panel, thereby forming a generally rectangular block having first and second faces. The block preferably further includes, among other components, at least one mounting bore for coupling a guardrail to a support post. The block preferably also includes an engagement mechanism operable to engage the block with the support post and a resting mechanism operable to support the guardrail during assembly.
In another aspect of the present invention, a method of manufacturing a spacer block for attaching a guardrail to a support post is provided. The method preferably includes forming a block, forming a first aperture through the block and positioning an engagement mechanism on the block, the engagement mechanism preferably being operable to retain the block proximate a mounting position during assembly of a roadway safety barrier system.
In yet another aspect, the present invention provides a guardrail support assembly. The guardrail support assembly preferably includes a support post and a spacer block. The spacer block preferably includes, among other characteristics, a top tab operable to engage the support post and maintain the spacer block in position.
In a further aspect, the present invention provides a method for assembling a roadway safety barrier system. The method preferably includes, among other steps, engaging a tab on a spacer block with a support post such that the spacer block is retained proximate a mounting position. The method preferably also includes engaging at least a portion of a guardrail with a support mechanism on the spacer block such that the guardrail segment may be retained in position proximate the mounting position.
In another aspect the present invention provides a roadway safety barrier system. The roadway safety barrier system preferably includes a guardrail, a support post and a spacer block coupled together by one or more attachment mechanisms. The spacer block preferably includes, among other elements, a positioning mechanism operable to depend the spacer block from the support during assembly of the roadway safety barrier system.
Further, the present invention provides a spacer block having improved strength, reduced weight, and competitive cost. In addition, the spacer block of the present invention, designed with the assembly process in mind, enables an individual installer to erect and install a guardrail safety barrier system using spacer blocks supported by posts.
Plastic properties are different from those of wood. The present invention takes advantage of these different properties through the use of a new spacer block design. The spacer block of the present invention may employ plastic (polyethylene, PVC, polypropylene polyethylene terephthalate, nylon), plastic/rubber, as well as other materials in its construction. Through the use of such materials, the present invention provides a more resilient, elastic and flexible spacer block that is generally impervious to weathering, has increased longevity, and requires little or no maintenance once installed.
It is an object of the present invention to provide a spacer block enabling one person to install a roadway safety barrier system.
It is another object of the present invention to provide a spacer block which is splinter-less, has a longer life span and is lighter than wood.
It is yet another object of the present invention to provide a plastic/rubber composite spacer block that meets all required specifications set forth by the Federal Highway Administration.
It is still another object of the present invention to provide a spacer block that is environmentally friendly and capable of being manufactured using recycled plastic, tires, and/or combinations thereof.
It is still another object of the present invention to provide a plastic-rubber composite spacer block that will meet or exceed the capabilities of today""s wooden block.
Yet another object of the present invention is to provide a spacer block embodiment that may be formed from structural foam in order to optimize the weight to strength characteristics of the spacer block.
Other objects, features, and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings showing a preferred embodiment of the invention.